Systems and methods for providing vacuum valve assemblies for end effectors

ABSTRACT

An end effector is disclosed for an articulated arm. The end effector includes a valve assembly including a plurality of supply channels, each supply channel including a supply conduit, a pressure sensor in fluid communication with the supply conduit, and a supply conduit plug. The supply conduit is in fluid communication with a vacuum source. During use, each supply conduit is either at vacuum such that the pressure within the supply conduit is substantially at a vacuum pressure, or is at a pressure that is substantially higher than vacuum pressure because the supply conduit plug has moved to block a portion of the supply conduit. The pressure sensor of each supply conduit provides a pressure sensor signal responsive to whether the pressure in the conduit is either substantially at vacuum or is at a pressure that is substantially higher than vacuum.

PRIORITY

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 62/210,246 filed Aug. 26, 2015, the disclosure ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND

The invention generally relates to robotic systems and relates inparticular to articulated arms that include end effectors that provide avacuum source for object acquisition or gripping.

Such vacuum grippers exist in many configurations in the prior art.Generally, such devices use compressed air to generate a vacuum by useof a Venturi pump. The vacuum is then presented at the object to beacquired through any one of a variety of interfaces.

One type of interface is a single large open port, which maximizes thesuction pressure from the vacuum and is thus well equipped to acquireheavy objects or those packaged in loose plastic. This configuration iscommonly referred to as a bag type gripper.

Another type of interface is an array of smaller ports, each of whichmay have integrated flow control (due to their small hole size) designedto close or reduce them if they are not making contact with the objectto be acquired. By closing unsealed ports, the suction pressure at portsthat have successfully mated with the object to be acquired should bemaximized. This approach provides flexibility in object acquisitionsince not all ports need to mate with an object in order to successfullyacquire it. This flow control is generally accomplished by means ofmetering (or making the ports small enough that the resulting leakagefrom an unsealed port is immaterial).

In other vacuum gripper systems, integrated check valves may be used inport chambers that contact the environment. Typically, such devicesinclude seals around the vacuum ports at the surface that meets theobject to be acquired. This approach, while being more mechanicallycomplicated, has the advantage of stronger overall suction force, sinceunsealed ports truly close at the opening, rather than just restrictingleakage flow. For single large ports, a large suction cup or foam ringis used. For the array of ports configuration, an array of suction cupsor a foam pad with holes for each of the individual ports are commonlyused.

In some vacuum gripper systems, a set of actuated valves is provided forthe air flowing through the gripper; a valve on the compressed air inputallows for shutting the vacuum on and off, allowing the gripper to dropan object. This approach, however, is slow due to time constants of airpressure equalization within the gripper body. The speed of release isdramatically increased by adding a second controlled valve to theexhaust port of the vacuum generator; by closing this valve, compressedair is diverted through the gripper body and out the vacuum ports,effectively blowing the acquired object off of the gripper surfacequickly.

The vacuum grippers in the prior art are generally designed for aspecific object or material in a predetermined orientation. The specificgripper style and configuration is chosen to optimize for a particularacquisition problem (for instance, palletizing and de-palletizing aparticular size/type of cardboard cartons). Such grippers are not at allwell suited to a wide array of objects in non-predeterminedorientations.

Further, in such vacuum gripper systems, software systems and algorithmsare provided that are developed around the concept of maximizing speedand efficiency of abort/retry cycles for robotic manipulators acquiringobjects. These algorithms have been focused in some applications onheavily instrumented multiple-finger mechanical grasping manipulators.The algorithms use the data from joint angles and motor power todetermine how well an object is grasped and immediately retry if thegrasp is not good enough.

In many such vacuum gripper systems, abort/retry techniques with vacuumgrippers are unsophisticated. These techniques generally consist ofapplying vacuum, lifting the gripper, and looking at coarse flow rate orweight sensors to determine whether an object has been acquired; if ithas not, the gripper is placed back on the object and acquisition isre-attempted. This is due largely to two reasons: 1) most currentlydeployed vacuum gripping systems are customized so heavily for thematerial being acquired that acquisition failures are rare, resulting inno real need for rapid abort and retry cycles, and 2) no vacuum grippersexist with the type of sophisticated instrumentation present in, forinstance, a multi-fingered grasping type end effector. The result isthat existing abort/retry algorithms cannot obtain from a vacuum gripperthe information they need to be able to operate.

There remains a need, therefore, for an improved vacuum gripper for usein an articulated arm that provides improved performance in acquiring awide variety of known and unknown objects.

SUMMARY

In accordance with an embodiment, the invention provides an end effectorfor an articulated arm. The end effector includes a valve assemblyincluding a plurality of supply channels, each supply channel includinga supply conduit, a pressure sensor in fluid communication with thesupply conduit, and a supply conduit plug. The supply conduit is influid communication with a vacuum source. During use, each supplyconduit is either at vacuum such that the pressure within the supplyconduit is substantially at a vacuum pressure, or is at a pressure thatis substantially higher than vacuum pressure because the supply conduitplug has moved to block a portion of the supply conduit. The pressuresensor of each supply conduit provides a pressure sensor signalresponsive to whether the pressure in the conduit is eithersubstantially at vacuum or is at a pressure that is substantially higherthan vacuum.

In accordance with another embodiment, the end effector includes a valveassembly including a plurality of supply channels, each supply channelincluding a supply conduit, a pressure sensor in fluid communicationwith the supply conduit, and a supply conduit plug. The supply conduitis in fluid communication with a vacuum source. During use, each supplyconduit is either at vacuum such that the pressure within the supplyconduit is substantially at a vacuum pressure, or is at a pressure thatis substantially higher than vacuum pressure because the supply conduitplug has moved to block a portion of the supply conduit. The padincludes a plurality of defined apertures, each of which is aligned witha respective supply conduit of the valve assembly, and the plurality ofdefined apertures in the pad include at least a first aperture and asecond plurality of apertures, and wherein the at least the firstaperture is centrally located with respect to the second plurality ofapertures

In accordance with a further embodiment, the invention provides a methodof providing a vacuum source to an end effector. The method includes thesteps of providing within the end effector a valve assembly including aplurality of supply channels, each supply channel including a supplyconduit, a pressure sensor in fluid communication with the supplyconduit, and a supply conduit plug, providing a vacuum source in fluidcommunication with the supply conduit, permitting the supply conduit tobe at a pressure that is substantially higher than vacuum pressure whenthe associated supply channel is not engaged with an object, permittingthe supply conduit to be at vacuum such that the pressure within thesupply conduit is substantially at a vacuum pressure when the supplychannel is engaged with an object, and providing a pressure sensorsignal responsive to whether the pressure in the conduit is eithersubstantially at vacuum or is at a pressure that is substantially higherthan vacuum.

BRIEF DESCRIPTION OF THE DRAWING

The following description may be further understood with reference tothe accompanying drawings in which:

FIG. 1 shows an illustrative diagrammatic view of an end effector inaccordance with an embodiment of the present invention;

FIG. 2 shows an illustrative diagrammatic view of a portion of the checkvalve plate of the end effector of FIG. 1 with a ball plug urged againstthe top plate and providing a single opening in connection with thecheck valve;

FIG. 3 shows an illustrative diagrammatic view of the portion of thecheck valve plate shown in FIG. 2 with the ball plug disengaged from thetop plate;

FIG. 4 show an illustrative diagrammatic isometric view of the sealingfoam of the end effector of FIG. 1;

FIG. 5 shows an illustrative diagrammatic bottom view of the sealingfoam of FIG. 4;

FIG. 6 shows an illustrative diagrammatic view of a portion of the checkvalve plate of the end effector of FIG. 1 with a ball plug urged againstthe top plate and providing vacuum to multiple openings in connectionwith the check valve;

FIG. 7 shows an illustrative diagrammatic view of the portion of thecheck valve plate shown in FIG. 6 with the ball plug disengaged from thetop plate;

FIG. 8 shows an illustrative diagrammatic block view of vacuum supplysystem for use with the end effector of FIG. 1;

FIG. 9 shows an illustrative diagrammatic view of an example of thevacuum supply system of FIG. 8;

FIGS. 10A and 10B show illustrative diagrammatic views of an endeffector cover for use with an end effector on an embodiment of theinvention;

FIG. 11 shows an illustrative diagrammatic isometric view of an endeffector in accordance with another embodiment of the invention;

FIGS. 12A-12D show illustrative diagrammatic views of end effectorcovers for use in accordance with further embodiments of the invention;and

FIG. 13 shows an illustrative diagrammatic view of mounting hardwareincluding load cells for mounting an end effector of the invention to arobotic arm.

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION

In accordance with various embodiments, the invention provides a newinstrumented hybrid-modality vacuum gripper system that has three mainfeatures as follows. First, the system provides hybrid modality. Thegripping surface is a unique design that incorporates the advantages ofboth the single large port configuration and the array of controlledports configuration of vacuum gripper, resulting in a single device thatis more effective than either previously existing configuration. Second,the system provides unique instrumentation. The gripper is mounted tothe end effector using a load cell array, such that controlling softwarehas precise knowledge of weights and torques being applied to thegripper by the acquired object. Each individual vacuum port in thegripping surface is also instrumented such that controlling software hasprecise knowledge of how well each individual port is gripping theobject that is being acquired. Third, the novel software and algorithmsprovide that presented sensor data may be used to maximize theefficiency of abort/retry cycles using this instrumented gripper. Thegeneral approach of hybrid modality, instrumentation, and algorithmsapplied to vacuum grippers is illustrated, in part, by the followingexamples.

The instrumented gripper assembly in accordance with an embodiment isshown in FIG. 1. The gripper assembly 10 includes a vacuum generationhead 12, a plenum block 14, a check valve plate 16, a screen plate 18and sealing foam 20 having gripping surfaces 22. The sealing foamincludes two sets of apertures, one set that is generally centrallylocated with respect to the other set as further shown in FIGS. 6 and 7.

The vacuum generation and control is provided by moving compressed airthrough a control valve to a Venturi pump, which creates a vacuum forthe gripper to distribute to the gripping surface. A second valve on theoutput of the Venturi pump allows one to blow-off acquired objects, asdescribed above.

The plenum block is provided below the Venturi pump, and the plenumblock distributes the generated vacuum to each of the individual portsin series by means of a channels that are machined into the block. Thisapproach minimizes the vacuum pressure required to check any individualport's control valve.

With further reference to FIG. 2, the check valve plate consists of anumber of chambers, each having a straight opening 30 at the bottom anda chamfered opening 32 at the top. A single such chamber (supplyconduit) 34 is shown in detail in FIG. 2, together with a supply conduitplug (ball) 36 and the opening to the vacuum plenum block 32, and apressure sensor 38. The pressure sensor 38 is responsive to the pressurewithin the chamber 34 and provides a signal to a printed circuit board40 in the check valve plate 16. The screen plate 18 includes a pluralityof screen openings in communication with chamber 34. Each of theopenings 30 and chambers 34 align with and are associated with a uniqueaperture in the sealing foam gripper 20, and each check valve assembly(including the chamber 34, opening 32, conduit plug 36 and pressuresensor 38) functions independent of the other check valve assemblies.

The top opening 32 mates to the plenum, thus providing a vacuum to thecheck valve chamber 34. The bottom opening 30 delivers the vacuumthrough the screen plate 18 to the bottom surface of the gripper 20, andthence to the object being acquired. The plug 36 in each check valvechamber is a plastic ball, of such a size and weight that if the bottomopening is open to atmosphere (i.e., not making contact with an objectto be acquired) and a vacuum is applied to the top opening, the plasticball 36 will be pulled by the vacuum up to the top opening, where itwill seat firmly against the chamfer there and effectively seal thatparticular check valve port. By using these types of ports, it isensured that any ports that are not actually making contact with anobject to be acquired are sealed and not bleeding off vacuum pressure.

The screen plate 18 mounts to the bottom of the check valve plate 16. Itconsists of a thin metal piece with openings that mate to each checkvalve. These openings are of such a size and shape (trefoil shape isused here) as to allow the ball 36 to sit on the opening without fallingout, and without sealing the lower opening 30. In this way, when theport is not making contact with an object to be acquired, air will flowthrough this opening, lifting the ball to the top of the chamber andsealing off that particular port. When the port is making contact withan object, the vacuum will be present in the chamber 34 and will holdthe object against the surface 22 of the gripper 20.

Of significance in this design is the incorporated printed circuit board40. The check valve plate is split into two pieces, top and bottom asshown in FIG. 2, and the printed circuit board 40 is sandwiched betweenthese two halves. On the printed circuit board 40 is mounted an array ofMEMS barometers, each of which is provided as a pressure sensor 38 for aport (again, a single port is shown in FIG. 2). These sensors (MEMSbarometers) are placed such that they are able to detect the airpressure in the bottom of the valve chamber near the gripper surface.Other openings 30 in the gripper 20 are associated with other valveassemblies (including other chambers, openings, conduit plugs andpressure sensors).

When a vacuum is applied to the gripper, ports that are contacting theobject being acquired will remain unchecked, meaning that the sensors inthose ports will read vacuum pressure (<<1 atmosphere). Any ports thatare not contacting the object will check, meaning the pressure in thebottom of the chamber will be equivalent to atmospheric pressure. Byreading all of the sensors, the software system will know exactly whichports are checked and which are making solid contact (and thus providinggripping force) to the object being acquired. Even once an object hasbeen acquired, if it starts to “peel off” of the gripper, or falls offcompletely, the sensor readings will change accordingly, allowing thesoftware system to know this in real time.

The gripper is circular at the gripping surface, as shown in FIGS. 4 and5. This shape and symmetry provide another degree of freedom to thesoftware control system. Again, the gripping surface 22 consists of anarray of ports, each of which has an integrated check valve and pressuresensor as described above. Further, the gripping surface is comprised oftwo sections, a radially inner section 50 and a radially outer section52. The sections are separated by a foam ring 54, which encloses thecentral grouping of apertures 58 and extends beyond the rest of thegripping surface. The second piece of foam fits around the outside ofthe first foam ring and extends to the outer edge of the grippersurface. It contains individual apertures 30 for each vacuum port.

The effect of this arrangement is a hybrid modality gripper combiningthe benefits of the single-large-port (or “bag”) configuration and thearray-of-controlled-ports configuration. The ports 58 in the middle (asshown in FIGS. 4 and 5) are all commonly open to each other within thefoam ring, so that they can achieve the suction strength of a singlelarge port while still being controlled with check valves. The foam ringis smaller and extends further than the rest of the gripping surface;this essentially acts as a secondary smaller gripper, allowing thisdevice to access and acquire smaller object surfaces where the largergripper could not otherwise fit. For larger items, simply pushing theentire device down to compress the foam ring will present the entiregripping surface to the object, allowing for compliant lifting of largeobjects with non-uniform surfaces.

FIGS. 6 and 7 show the portion of the check valve plate that providesthat multiple ports in the gripper may be commonly in communication witha single vacuum source. In particular, the central portion of the checkvalve plate includes a chamber 70 having straight openings 58 at thebottom and a chamfered opening 72 at the top. A single such chamber(supply conduit) 70 is shown in detail in FIG. 6, together with a supplyconduit plug (ball) 76 and the opening to the vacuum plenum block 72,and a pressure sensor 74. Again, the pressure sensor 74 is responsive tothe pressure within the chamber 70 and provides a signal to the printedcircuit board 40 in the check valve plate 16. The screen plate 18includes screen openings aligned with chamber 70. Each of the openings58 are in communication with the chamber 70.

The top opening 72 mates to the plenum, thus providing a vacuum to thecheck valve chamber 70. The bottom openings 58 deliver the vacuumthrough the screen plate 18 to the bottom surface of the gripper 20 inthe inner area 50 as a common group of apertures, and thence to theobject being acquired. Again, the plug 76 in the check valve chamber isa plastic ball, of such a size and weight that if the bottom opening isopen to atmosphere (i.e., not making contact with an object to beacquired) and a vacuum is applied to the top opening, the plastic ball76 will be pulled by the vacuum up to the top opening, where it willseat firmly against the chamfer there and effectively seal thatparticular check valve port as shown in FIG. 6. By using these types ofports, it is ensured that any ports that are not actually making contactwith an object to be acquired are sealed and not bleeding off vacuumpressure. When the port is not making contact with an object to beacquired, air will flow through this opening, lifting the ball to thetop of the chamber and sealing off that particular port. When the portis making contact with an object, the ball 76 will drop (as shown inFIG. 7) and the vacuum will be present in the chamber 70 and will holdthe object against the surface of the gripper 20 in the inner area 50.

This hybrid modality allows for successful acquisition of a much broaderspectrum of objects than either prior type of vacuum gripper by itself.Heavy objects in plastic bags (e.g., a bag of oranges) typically cannotbe acquired by standard port-array type vacuum grippers, but only bysingle large port type grippers; the central port grouping on the novelgripper presented here can acquire these objects. Another example is abottle of shampoo standing upright; a typical single large port typegripper will be too large to seal to the top of the cap, and thus willnot acquire the object. The novel gripper here can use a single portfrom the outer ring to seal to the shampoo cap; all other ports,including the central group, will check, allowing this device tosuccessfully acquire the object. In other embodiments, different vacuumpressures may be applied to the inner set of apertures as compared tothe outer set of apertures in a variety of ways, including for example,restricting air flow in the outer set of apertures.

This combination of power and flexibility is unique and powerful. Bycombining the benefits of multiple configurations, the result is greatlyreduced or eliminated need for tool changing, along with the associatedcost and time.

In accordance with certain embodiments, the invention further provides asystem for providing high flow vacuum control to an end effector of anarticulated arm. In accordance with various embodiments, the inventionprovides a dynamic high flow gripping system, and may optionally includea mechanism to select between the high flow source and a high vacuumsource, depending on the application. High flow vacuum systems of theinvention may therefore optionally be used with high vacuum sources.

The system, for example, may include a first vacuum source for providinga first vacuum pressure with a first maximum air flow rate (to forexample, the inner area 50), and a second vacuum source for providing asecond vacuum pressure with a second maximum air flow rate (to forexample, the outer area 52). In certain embodiments, the second vacuumpressure is higher than the first vacuum pressure and wherein the secondmaximum air flow rate is greater than the first maximum air flow rate.The reverse also possible in other applications. The flow rates arecharacterized as maximum air flow rates because, when an object isengaged at an end effector, the flow rate may drop significantly. Thehigh flow source may be used together with a high vacuum source, or as asingle source.

FIG. 8, for example, shows a system 100 for use with an end effector inaccordance with an embodiment of the present invention in which anoptional high vacuum source 102 is provided as well as a high flowsource 104 and a release source 106 that are each coupled to a selectionunit 108, that is coupled to an end effector 110. The selection unit 108selects between the high vacuum source 102, high flow source 104 and therelease source 106 for providing any of high vacuum, vacuum with highflow, or a release flow to the end effector. FIG. 8 therefore shows ageneral form of the invention, comprising mechanisms for producing highvacuum and high flow, a release source providing either atmosphericpressure via a vent or high pressure (blow off) via a compressor orreservoir, and a mechanism for selecting the source best suited to thepresent situation.

In particular, FIG. 9 shows a system 120 in accordance with anembodiment of the invention that includes a compressor 122 that iscoupled to an ejector 124 to provide a high vacuum source that iscoupled to a solenoid valve 126. A blower 128 is also coupled to thesolenoid valve 120 via a non-return valve 130, and the blower 128provides a vacuum source with a high maximum flow rate. A vent orblow-off source is also provided to the solenoid valve 120, the outputof which is provided to an end effector 132. The system therefore,provides the ejector 124 as the high vacuum source, the regenerativeblower 128 as the high flow source, the non-return valve 130 as apassive selection mechanism, and the solenoid valve 120 connecting theeffector to the release source, either vent or blow-off.

The vacuum pressure provided by the ejector 124 may be, for example, atleast about 90,000 Pascals below atmospheric and the vacuum pressureprovided by the blower 128 may be only no more than about 25,000 Pascalsbelow atmospheric in some examples, and no more than about 50,000Pascals below atmospheric in other examples. The vacuum pressureprovided by the blower 128 is therefore higher than the vacuum pressureprovided by the ejector 124. The maximum air flow rate of the ejectormay be, for example, no more than about 5 cubic feet per minute (e.g.,1-2 cubic feet per minute), and the maximum air flow rate of the blowermay be, for example at least about 100 cubic feet per minute (e.g.,130-140 cubic feet per minute).

In accordance with certain embodiments, therefore, end effectors of theinvention may include a central region of a gripper surface thatprovides high flow gripping. In further embodiments, the surface at thecentral region of the gripper may include a specialized opening coverfor use with a high flow vacuum gripper. In particular and as shown inFIGS. 10A (articulated arm facing side) and 10B (object facing side),such a cover 140 may include a proximal back side 142 that does notpermit air to flow through the material, and distal front side 144 forengaging objects that is formed of a foam material. Slit openings 146 inform of a star or asterisk shape are provided through the material inthis example. During use, elongated objects may be received alongopposing slit openings and held by the foam material.

The compliant foam on the surface 144 contacts the object to beacquired, giving the gripper some compliance while also acting to sealthe aperture around the object as the foam is compressed and the highflow vacuum is applied. The aperture cover therefore allows a high flowgripper to effectively pick up long narrow objects with an easy toattach cover that may be held in a tool changer and added or removedfrom the gripper autonomously during real-time operation

FIG. 11 shows an end effector gripper 150 having such a cover 140 usedin connection with a gripper surface having an outer section 52 asdiscussed above, and an inner section 152 providing high flow throughthe cover 140. The cover may also be flush with the circular wall 54 asshown.

A system is therefore provided in an embodiment, for providing vacuumcontrol to an end effector of an articulated arm, where the systemincludes a vacuum source for providing a vacuum pressure at a flow rateto the end effector, and the end effector includes a cover that includesan opening that varies significantly in radius from a center of thecover. The opening may include finger openings that extend radially fromthe center of the opening. The opening may be generally star shaped orasterisk shaped. The cover may include compliant foam on a distal sideof the cover that engages an object to be grasped, and an air flowresistant material on a proximal side of the cover. The vacuum pressuremay be no more than about 50,000 Pascals below atmospheric, and the airflow rate may be at least about 100 cubic feet per minute.

The invention therefore provides a system for providing vacuum controlto an end effector of an articulated arm, where the system includes avacuum source for providing a vacuum pressure at a flow rate to the endeffector, and the end effector includes a cover including an air flowresistant material on a proximal side of the cover and a compliantmaterial on a distal side of the cover for contacting objects to begrasped. The cover may include an opening that varies significantly inradius from a center of the cover, and the opening may include fingeropenings that extend radially from the center of the opening. Theopening may be generally star shaped or asterisk shaped. The cover maybe formed of a compliant material and include compliant foam on a distalside of the cover that engages an object to be grasped, and the covermay include an air flow resistant material on a proximal side of thecover. The vacuum pressure may be no more than about 25,000 Pascals or50,000 Pascals below atmospheric, and the air flow rate may be at leastabout 100 cubic feet per minute.

Covers with other types of openings are shown in FIG. 7A-7D. FIG. 7A,for example, shows a cover 160 that includes slit openings 162. FIG. 7Bshows a cover 170 that includes different sized square openings 172,174. Cover 180 shown in FIG. 7C includes small circular openings 182,and cover 190 shown in FIG. 7D includes differently shaped openings 192and 194. In each of the covers 140, 160, 170, 180 and 190, a compliantfoam surface may face the object to be acquired, and more area of thecover is provided to be open closer to the center of the cover withrespect to the outer periphery of each cover. For example, in the cover140, the center of the astricks shape is most open. In the cover 160,the larger slits are provided in the center. In the cover 170, thelarger square openings are provided in the center. In the cover 180, thegreater concentration of the circular openings is provided in thecenter, and in the cover 190, the lager shape 192 is provided in thecenter.

The gripper assembly may be mounted to the end of a wide variety of 4-or 6-axis robotic arms. The mounting assembly 200 incorporates loadcells, as shown in FIG. 13. There are four load cells 202, placedbetween the mounting bracket 204 at the end of the robotic arm and thetop surface of the gripper body 206. One of these load cells is placedat each corner of the gripper body, allowing the SW system to preciselyknow the distribution of weight of an acquired object and the resultingforces and torques that the object is placing on the gripper. Thesesensors will also detect if an object has fallen off of the gripperduring acquisition or movement; the Software system will integrate thisdata with the data provided by the array of pressure sensors in thecheck valve block to provide input to the algorithms that are maximizingabort/retry efficiency and speed.

The system therefore, does not require the use of sophisticated softwarealgorithms that use probabilistic and predictive processes to maximizespeed and efficiency of acquisition/failure/abort/retry cycles withmulti-fingered hand-type grasping end effectors. These algorithms relyon precise data about joint angles and motor speeds/currents/torques aswell as image data from 2D or 3D camera systems to know whether or notan acquisition has been successful and plan a retry if necessary.Because vacuum grippers have previously lacked any type of similarlysophisticated sensing, and because previous applications have beenlimited and highly controlled, these algorithms have not been appliedpreviously to vacuum gripping situations.

The novel gripper described here provides such data using inexpensivesensors (load cells and MEMS barometers). When the gripper is placed onan object and the vacuum is enabled, the software control system willimmediately have a map of which ports are providing suction to theobject and which are checked closed. With a priori knowledge of theobject (from 2D/3D imaging and database matching, for instance), the SWwill be able to calculate a success percentage for object acquisition.

If the percentage is below a threshold, the control system can shut offvacuum and reposition the gripper to try again quickly without having toactually attempt and fail at acquisition first. This will greatlyenhance retry speed.

If the percentage is above some threshold, the control system can raisethe gripper. At this point, the data from the load cell array will beginto tell the control system whether or not the object weight is beinglifted, and at what position and torque. As the object is being moved,the load cell and port pressure data will also warn the control systemif the acquisition is failing and the object is going to fall, allowingthe control system to take appropriate action.

This data will provide the software control system a real time pictureof where, how, and how well an object is acquired, from before thegripper has even been moved all the way through object delivery andrelease. This data can be used by a software control system as input forefficient abort/retry algorithms previously only used by moresophisticated manipulators.

The instrumented hybrid-modality vacuum gripper presented heretherefore, combines the benefits of prior vacuum gripper configurationsinto a single device, at the same time integrating sensors that providethe kind of detailed acquisition data needed to enable advancedabort/retry efficiency software algorithms previously reserved for moresophisticated multi-finger type grippers. The result is a singleinexpensive end effector that can be used to rapidly and efficientlyacquire and move a very broad spectrum of object types, sizes, weights,and packaging types, in a variety of orientations.

Those skilled in the art will appreciate that numerous modifications andvariations may be made to the above disclosed embodiments with departingfrom the spirit and scope of the present invention

What is claimed is: 1.-20. (canceled)
 21. A vacuum control system for anend effector attached to articulated arm, said vacuum control systemcomprising: a high pressure vacuum source coupled to a selectionmechanism for selectively providing high vacuum to the end effectorincluding a vacuum pressure of at least about 90,000 Pascals belowatmospheric: a high flow vacuum source coupled to the selectionmechanism for selectively providing high flow vacuum to the end effectorincluding a vacuum flow of at least about 100 cubic feet per minute; anda supply conduit plug that is movable between an open positionresponsive to a supply conduit being at vacuum such that the pressurewithin the supply conduit is substantially at a vacuum pressure, and aclosed position responsive to the supply conduit being at a pressurethat is substantially higher than vacuum pressure because the supplyconduit plug has moved to block a portion of the supply conduit; whereinsaid end effector includes at least one first aperture that is centrallylocated with respect to a second plurality of apertures, and wherein theat least the first aperture is selectively coupled to the high pressurevacuum source, and the second plurality of apertures is selectivelycoupled to the high flow vacuum source.
 22. The vacuum control system asclaimed in claim 21, wherein the at least the first aperture is providedtogether with a plurality of first apertures that are commonly incommunication with the selection mechanism.
 23. The vacuum controlsystem as claimed in claim 22, wherein said end effector furtherincludes a compliant pad at a distal end of the end effector.
 24. Thevacuum control system as claimed in claim 23, wherein said compliant padincludes a plurality of defined apertures, each of which is aligned witha respective supply conduit of said valve assembly.
 25. The vacuumcontrol system as claimed in claim 24, wherein said plurality of definedapertures in the complaint pad include a first plurality of aperturesand a second plurality of apertures, and wherein the first plurality ofapertures are centrally located with respect to the second plurality ofapertures.
 26. The vacuum control system as claimed in claim 25, whereinthe first plurality of apertures is separated from the second pluralityof apertures by a wall.
 27. The vacuum control system as claimed inclaim 26, wherein the wall is a ring formed of a compliant material. 28.The vacuum control system as claimed in claim 21, wherein the supplyconduit further includes a pressure sensor, wherein the pressure sensorprovides a pressure sensor signal responsive to whether the pressure inthe respective supply conduit is either substantially at vacuum or is ata pressure that is substantially higher than vacuum.
 29. The vacuumcontrol system as claimed in claim 28, wherein said end effector furtherincludes an electronic circuit board in communication with the pressuresensors that is associated with the supply channel.
 30. The vacuumcontrol system as claimed in claim 29, wherein said pressure sensorsignal is provided to the electronic circuit board to provideinformation indicative of whether the supply channel is engaged with aload, thereby reducing the vacuum pressure within the respective supplychannel.
 31. The vacuum control system as claimed in claim 21, whereinthe high pressure vacuum source and the high flow vacuum source arecoupled to the articulated arm via a mounting plate, and wherein themounting plate is coupled to the vacuum head via a plurality of loadcells that are each responsive to force distributions.
 32. The vacuumcontrol system as claimed in claim 31, wherein said end effector furtherincludes a plurality of load cells attached between an articulated armand a vacuum generation head that provides the vacuum pressure.
 33. Avacuum control system for an end effector attached to articulated arm,said vacuum control system comprising: a high pressure vacuum sourcecoupled to a selection mechanism for selectively providing high vacuumto the end effector including a vacuum pressure of at least about 90,000Pascals below atmospheric: a high flow vacuum source coupled to theselection mechanism for selectively providing high flow vacuum to theend effector including a vacuum flow of at least about 100 cubic feetper minute; and a plurality of supply channels, each of which includes asupply conduit and a supply conduit plug that is movable between an openposition and a closed position responsive a pressure with the supplyconduit; a first plurality of apertures that are in communication withthe plurality of supply channels that are centrally located with respectto a second plurality of apertures, and wherein the first plurality ofaperture are selectively coupled to the high pressure vacuum source, andthe second plurality of apertures is selectively coupled to the highflow vacuum source.
 34. The vacuum control system as claimed in claim33, wherein the first plurality of apertures are commonly incommunication with the selection mechanism.
 35. The vacuum controlsystem as claimed in claim 34, wherein said end effector furtherincludes a compliant pad at a distal end of the end effector.
 36. Thevacuum control system as claimed in claim 35, wherein said compliant padincludes a plurality of defined apertures, each of which is aligned witha respective supply conduit of said valve assembly.
 37. The vacuumcontrol system as claimed in claim 36, wherein said plurality of definedapertures in the complaint pad include a first plurality of aperturesand a second plurality of apertures, and wherein the first plurality ofapertures are centrally located with respect to the second plurality ofapertures.
 38. The vacuum control system as claimed in claim 37, whereinthe first plurality of apertures is separated from the second pluralityof apertures by a wall.
 39. The vacuum control system as claimed inclaim 38, wherein the wall is a ring formed of a compliant material. 40.The vacuum control system as claimed in claim 33, wherein each supplyconduit further includes a pressure sensor, wherein the pressure sensorprovides a pressure sensor signal responsive to whether the pressure inthe respective supply conduit is either substantially at vacuum or is ata pressure that is substantially higher than vacuum.
 41. The vacuumcontrol system as claimed in claim 40, wherein said end effector furtherincludes an electronic circuit board in communication with each pressuresensors that is associated with each supply channel.
 42. The vacuumcontrol system as claimed in claim 41, wherein each pressure sensorsignal is provided to the electronic circuit board to provideinformation indicative of whether the respective supply channel isengaged with a load, thereby reducing the vacuum pressure within therespective supply channel.
 43. The vacuum control system as claimed inclaim 33, wherein the high pressure vacuum source and the high flowvacuum source are coupled to the articulated arm via a mounting plate,and wherein the mounting plate is coupled to the vacuum head via aplurality of load cells that are each responsive to force distributions.44. The vacuum control system as claimed in claim 43, wherein said endeffector further includes a plurality of load cells attached between anarticulated arm and a vacuum generation head that provides the vacuumpressure.
 45. A vacuum control system for an end effector attached toarticulated arm, said vacuum control system comprising: a high pressurevacuum source coupled to a selection mechanism for selectively providinghigh vacuum to the end effector including a vacuum pressure of at leastabout 90,000 Pascals below atmospheric: a high flow vacuum sourcecoupled to the selection mechanism for selectively providing high flowvacuum to the end effector including a vacuum flow of at least about 100cubic feet per minute; and a plurality of supply channels, each of whichis in communication with the selection mechanism and with one of a firstplurality of apertures of the end effector; said first plurality ofapertures being centrally located with respect to a second plurality ofapertures, and wherein the first plurality of aperture are selectivelycoupled to the high pressure vacuum source, and the second plurality ofapertures are selectively coupled to the high flow vacuum source. 46.The vacuum control system as claimed in claim 45, wherein the firstplurality of apertures are commonly in communication with the selectionmechanism.
 47. The vacuum control system as claimed in claim 46, whereinsaid end effector further includes a compliant pad at a distal end ofthe end effector.
 48. The vacuum control system as claimed in claim 47,wherein said compliant pad includes a plurality of defined apertures,each of which is aligned with a respective supply conduit of said valveassembly.
 49. The vacuum control system as claimed in claim 48, whereinsaid plurality of defined apertures in the complaint pad include a firstplurality of apertures and a second plurality of apertures, and whereinthe first plurality of apertures are centrally located with respect tothe second plurality of apertures.
 50. The vacuum control system asclaimed in claim 49, wherein the first plurality of apertures isseparated from the second plurality of apertures by a wall.
 51. Thevacuum control system as claimed in claim 50, wherein the wall is a ringformed of a compliant material.
 52. The vacuum control system as claimedin claim 45, wherein each supply conduit further includes a pressuresensor, wherein the pressure sensor provides a pressure sensor signalresponsive to whether the pressure in the respective supply conduit iseither substantially at vacuum or is at a pressure that is substantiallyhigher than vacuum.
 53. The vacuum control system as claimed in claim52, wherein said end effector further includes an electronic circuitboard in communication with each pressure sensors that is associatedwith each supply channel.
 54. The vacuum control system as claimed inclaim 53, wherein each pressure sensor signal is provided to theelectronic circuit board to provide information indicative of whetherthe respective supply channel is engaged with a load, thereby reducingthe vacuum pressure within the respective supply channel.
 55. The vacuumcontrol system as claimed in claim 45, wherein the high pressure vacuumsource and the high flow vacuum source are coupled to the articulatedarm via a mounting plate, and wherein the mounting plate is coupled tothe vacuum head via a plurality of load cells that are each responsiveto force distributions.
 56. The vacuum control system as claimed inclaim 55, wherein said end effector further includes a plurality of loadcells attached between an articulated arm and a vacuum generation headthat provides the vacuum pressure.